The electroforming production of jewellery parts such as, for example, Creoles, buckles of ears, pendants, cross, bracelets, necklaces, rings, signet rings, spits, etc . . . is well known.
It consists in reproducing an object electrolytically from an accurately designed model, with the location for stones that have to be embedded on the surface into seats provided for this purpose.
For example, classically, to realize a Creole, a bulky base made with a tin alloy having externally the forms and dimensions of the Creole desired to obtain, less the thickness of the gold layer that will be electro-deposited, is prepared. The base is then coated by electrodeposition of a very thin copper layer in order to separate the gold layer from that of tin, then of a gold layer that can vary between 120 and 450 micrometers according to the desired weight of the jewel.
The deposit process for gold proceeds in the following manner. On the copper layer and before installation of stones, a thin gold layer, for example, of about fifteen micrometers is deposited. The stones are then installed into receiving accommodations. A new gold layer is deposited, with a thickness ranging, for example, between 100 and 400 micrometers, followed by a protecting copper layer.
Then, the base made of tin is thermally extracted, and the copper removed by a chemical processing.
Thus, a hollow Creole with stones imprisoned into the surface is obtained, whose forms and reliefs are determined by those of the base that the gold has contoured by a thin layer deposit.
Due to the low thickness of the gold layer forming the wall of the Creole that varies between 120 and 450 micrometers, it is nearly impossible to install a stone by traditional setting due to the lack of material to do this operation.
Furthermore, one could intend to retain stones in place by the single gold layer deposited after installation of stones, but in order to obtain a solid setting it would be necessary to deposit a gold layer having too large a thickness, the face of stones that is oriented toward the interior of the accommodations not being subjected to a setting complementary to that of the visible face because the deposit bath cannot access said accommodations.